US2171223A - Racket for tennis and batting games and method of manufacturing same - Google Patents

Description

Aug. 29, 1939. R. H. ROBINSON 2,171,223

BASKET FORTENNIS-AND BATTING GAMES AND METHOD OF MANUFACTURING SAME Original Filed June 15, 1931 e sheetssheet 1 Aug. 29, 1939. R. H. ROBINSON 2,171,223

. RAFCKET FOR TENNIS AND BATTING GAMES AND ME'AIHOD 0F MANUFACTURING SAME -Original Filed June 15, 1951 6 Sheets-Sheet 2 {ar/f ug. 29, 1939. R. H. ROBINSON 2,171,223

I RACKET Fon TENNIS AND BATTING GAMES AND METHOD 0F MANUFACTURING SAME Original Filed June 15, 1951 6 Sheets-Sheet 5 R. H. ROBINSON Aug. 29, 1939".

RACKET FOR TENNIS AND BATTING GAMES AND METHOD 0F 'MANUFACTURING SAME 6 Sheets-Sheet 4 Original Filled June l5, 1951 O O vO OV au l o 0 9 rLLl/l l A BOG Aug. 29, 1939. R. H, RoBlNsoN 2,171,223 RACKET FOR TENNIS AND BATTING GAMES ND METHOD OF MANUFACTURING SAME Original Filed June 15, 1931 6 Sheets-Sheet 5 k "j *31a i f2 vif "dd Imfenfo' Aug. 29, 1939. R: H. ROBINSON 2,171,223v RACKET FOR TENNIS AND BATTING GAMES AN METHOD OF MANUFACTURING SAME A Original Filed June l5, 1931 6 Sheets-Sheet 6 Patented Aug. 29, 1939 RACKET FOR TENNIS AND METHOD F SAME- my n. einem, carcasa, nl. substitute mr abmeesesappueauon serai No. Y.

544,361, June 15, 1931.

This application cember 2, 1937, Scritti N0. 177,332

52 Claims. im. 273-73) This invention, covered by this application, which is a substitute for .applicantfs abandoned application #544,361 filed June 15, 1931, relates to rackets strung for tennis, squash tennis, racquets, badminton and kindred games, and more particularly to those which are provided with a tubular and particularly a metal frame.' and has for its primary object, the improvement in the method of manufacturing Same, and the obtaining of exceptional resilience in the Stringing, lightness of weight, and a light head for securing the balance particularly demanded by present day players. f

The purpose o f the invention, furthermore, is to secure a maximum of speed in play, by combining highly resilient and preferably non-metallic Stringing in a metal frame in Such manner as not to injure the Stringing, and at the saine time, permit the exceptional tautness, and to greatly augment the resilience of the stringing by supplementing this with an added resilience in the reaction of the frame itself inV returning the balls' off the Stringing.

The invention furthermore, consists of certain novel improvements or variations in the con- I struction disclosed in myprior Patents #1,470,- 878 of October 16, 1923; #1,676,051 of July 3, 1928; in my formerly co-pending applications Serial #170,777 tiled February 25, 1927; #284,- 981 filed June 13, 1928; and #366,131 filed May 27, 1929, maturing into Patents #1,862,581 issued June 14, 1932; #1,937,787 issued December 5,

- 1933; and #1,930,285 issued October 10, 1933,

respectively, as Well as embodyingother features which improve the racket, simplify the construction, and greatly facilitate the' speed and economy of manufacture.

Because of its high strength-weight ratio in meeting Ithe great variety of stresses to which the frame of a tennis racket is subjected, successful metal frames employed in the game are generally formed of metal tubing. The difliculties of forming and fabricating tubing are well known and peculiar to its hollow-formation. In small thin Walled tubing, required bythe -we'ight limitation of tennis and other rackets, this work is peculiarly difficult and expensive.

Hitherto, it has been found necessary to bnd the tubing into the oval, round or curved racket head before forming the holes for receiving the' Stringing, otherwise the tube buckles and stretches at the holes in the bends, the holes being distorted by buckling on one side and stretching on the opposite side of the -bent tube. Because of this`and the very small size of the tubing, it has been found necessary after bending the tube to drill or spin the holes in individually at relatively great expense, as compared with punch press work, not feasible under these old methods.

One of the primary objects of my invention is to provide a means of fabricating metal tubing portion of the fabricating is press work, and to provide a method whereby the Stringing holes in lfor the curved racket heads, whereby ,a large successfully resist the tremendous torsional -Strains of exceptionall;r hard hitting and yet permit the Stringing holes in the tubing to be larger than customary in order to accommodate both the strings and my protectivestringing guides, which protect the string from the abrasion, metal strain or cutting and permit the use of gut, silk, or other non-metallic Stringing, the use 'of which is not successful or feasible in the present metal frame rackets on the market. These larger holes for string guides in' the tube weaken the frame and so provide a problem which Isuocessfully meet.

.A further improvement provided by `my method' of manufacture is to permit sharp bends or turns in the metal tubing forming the racket head,

y whereby a smaller, yet more efficient playing area is secured in the racket head eliminating Waste or dead space of little use in hitting the bail.' I so reduce the length of the Stringing span -not only making the strings faster, but procuring a great saving in the cost of the gut, which in the longer lengths is relatively much more costly. I likewise so reduce the air resistance in playing the racket, by so eliminating the useless areas found in wooden and present day metal rackets,

.vt-here the sharp bends in the wood frame or metal tubing are not feasible or desirable from a manufacturing standpoint.

A further object of my invention is to provide Ways and means for Stringing the racket head to secure a maximum tautness and resilience in the Stringing and subsequently take up any give occurring in the non-metallic' Stringing supports and guides, or the siackening of the Stringing due to. age, play, or other causes; and likewise to provide a desired and relieving give to the Stringing when it is too greatly' strained by weather conditions or play, or by the spring reactionsof the frame.

A further object is to provide light weight string guides and supports for protecting the Stringing from the metal frame, which are easily .removable and replaceable when desired in restringing the racket frame at any time. A further object is to provide a handle and ferrule construction of unusual and attractive appearance combined with great Strength and Security in its attachment to the metal frame.

and reinforcgthe metalv parts `of the racket frame as to gradually distribute the abrupt stroking stresses and so avoid snapping the frame, and to strengthen the racket at the points of inherent weakness or greatest stress and to add resilience and whip to the frame thereby.

The invention consists of these and other novel features, which will be brought out in the following description.

In the accompanying drawings:

Fig. 1 is a. plan view of. a racket built in accordance with the invention.

Fig. 2 is a side elevation of the racket.

Fig'. 3 is a fragmentary side'elevation of the string supporting strip for insertion in the racket frame.

Figs. 4 and 5 are sectional views of the racket frame 'taken'on the section lines d-d and 5-5 of Figure 1.

Fig. 6 is a sectional view of the handle on the I section line 6--6 of Figure 1. Fig. 7 is a fragmentary elevation of the racket frame and details of the Stringing strip.

Fig. '7a is a fragmentary elevation showing an alternate form of -stringing strip.

Fig. 8 is a fragmentary sectional plan view of the frame and Stringing strip.

Fig. 11 is a sectional view through the upper portion of the ferrule securing the handle on section line lll-l ll of Figure Il. y

Fig. 12 is a fragmentary plan view of a modified form of the racket embodying a special recoil spring.

Fig. 13 is a sectional. view of the recoil spring shown in Figure 12.

Fig. 14 is a fragmentary side elevation of the racket showing the ferrule arrangement of Figure 12.

Fig. 15 is another fragmentary plan view of another modified form of the racket.

Fig. 16 is a. plan view of a spring bridge piece.

Fig. 17 is a plan view of another form of the spring bridge piece.

Fig. 18 is a fragmentary plan View of an alternate end construction of the spring bridge piece.

Fig. 19 is a. fragmentary plan view of a frame reinforcing end for the spring bridge piece.

Fig. 20 is a fragmentary plan view showing the construction of the stamped ring anchorages of the stamped `reinforcements employed in the racket Figure 12.

Fig. 21 is a plan of another form of the racket. 1

Fig. 22 is a fragmentary elevation of the central portion of the spring bridge shown in Figure 17.

Figs. 23 and 23a are sectional views of the -frame of the racket showing dierent arrangements of sheathing and string cushioning.

` racket.

Fig. 2'1 is aqfragmentary sectional view of tubing used in forming the racket frame.

Fig.` 28 is a fragmentary sectionalview showing method of punching the tubing.

Fig. 29 is a fragmentary sectional view showing method of channeling the tubing before punching, when desired.

Fig. 30 is a. fragmentary sectional view showing position in which the prechanneled tube is punched.' 4 f Fig. 3 1 is a fragmentary sectional view showing the position of the punched tubing in the nal molding die after bending and before fiattening or molding.

Fig. 32. is a fragmentary sectional view showing the section of the racket frame in the molding or fiattening die after the molding operation is completed.

Fig. 33 isa cross sectional view of a racket frame showing the regular form of the string guide holesproduced in the frame.

Fig. 34 is a cross sectional view of a frame showing an alternate form for the string guide holes and alsoa.' special Stringing strip for padding the end of the racket frame in squash and certain indoor games.

',Fig. 35 is a, fragmentary plan diagram of exaggerated proportions showing the plany view` (in the straight) of a piece of tubing of constant diameter, and the relation of the varying Widths of its face when formed to a racket head such as used in Figure 1.

Fig. 36 is a fragmentary elevation diagram corresponding to Figure 35 showing the side elevation of the same piece of tubing, and the relation of ythe 'varying depths of its sides as formed for a racketpof the type of Figure 1.

, Fig. 37 is a fragmentary elevation diagram similar to Flgure showing a side elevation of the piece of tubing when stepped ofi on its top and ,bottom facesl(in lieu`of graduated tapering)to simulate the effect of a stepped racket frame of thetype in Figure 21.

Fig..'38is"another similar fragmentary elevation diagram indicating the side elevation of another'racket frame tube, shown in the straight, where the tubing is of varying diameters, stepped up at spaced intervals, the stepping completely the .right anglev stepping shown in Figure 38.

Fig. 39 is a fragmentary elevation diagram similar to Figure 38 with the exception that the stepping instead of being formed squarely or diagonally on the tubing, is formed with converging V lines'on opposite faces.

Fig. 40 is a similar fragmentary elevation diagram showing straight and tapering lines`in a formed 4seamed tube of varying diameter for a racketframe (shown in the straight).

Fig. 41 is a similar fragmentary elevation diagram ofv a seamed tubing similar to that shown in Figure 40, where the form, however, is a straight taper from each end to the center of the racket frame tubing (as shown in the straight). v

Fig. 42 is a plan view of one form of the racket. Fig. 43 is a side elevation of this form of the Fig. 44 isa plan view of Aa modified form of the racket. f

Fig. 45 is. a side elevation of this modied form of the racket.`

Referring in' detail to the drawings, Figure 1 spread on varying centers, those at the outer end representsv the racket, the frame of' the racket head being of rtubular formation. The walls o f the tube may be of either metal or non-metallic material, but it is preferable, in order to 'secure the smallest section possible and thereby reduce sequently noted.

the air resistance in play tothe minimum,` to use steell alloy of exceptionally high tensile strength and resiliency with pronounced resistance'to metal fatigue, the physical properties being developed by heat treating and drawing. The tubular frame is preferably so shaped as to taper in'thickness, from a minimum thickness;

at the outerend of the racket head where in hitting, the strain in relation to frame depth is the least; toA amaximum thickness at thethroat end of the racket, where due` to the greater leverage 0f the racket blow and the weakening oscasioned by necessary Stringing holes, the 'tubular frame is so formed to a maximum depth or` ing preferably maintaining a regular untapered Shape throughout its length within the wooden handle. Either straight or a partially tapered tubing can be used in shaping the frame to conformto the above provisions.

The tube itself is channeled on the outside,

the channel 4 preferably, though not necessarily, i

extending fromthe outer end all the way down the racket head so as to finally die out atthe Shanks below the sharp curve'of the throat, but above the ferrule as indicated in Figures 1 and 22. The channel, however, can be continued the full length of the frame tubing down into the ferrule, or on the other hand, stopped part way down the sides of the head, if so desired as will be sub- It is essential, however, for the protection of the Stringing, thatthe channel at leastcontinue across theouter end of the head and far enough down the sides, so that in 4any case the Stringing is protected from hitting the ground. It will be observed that in accordance with the sections, Figures 4 and 5, the channel is relatively very deep at the outer end o1 the racket head where the Stringing must be particularly protected, While at the innerend where this protection is not required, the channel is shallower in depth. i

The Stringing in the racket head is supported on and woven through a string supporting and protecting strip 5, which lies in the channel il. This string support maintains the racket strings t away fromthe cutting edges or abrading surfacesv of the metal frame, in accordance with my previous patents and applications noted, so as to permit the use of delicate and highly resilient gut Stringing, and relieve momentary and excessive strains on the strings, and deaden the vibrations, which would otherwise be imparted from the Stringing to the metal frame and thence `to the handle. This string support is composed preferably of a small fabric tape l, which. is impregnated with a Suitable molding material, thermoplastic or otherwise, which forms with the textile base a.relatively thin and narrow band of insignificant weight,lpreferab1y only 11a" to gif" thick. 'I'his band, in the molding or forming, has

provided on its inner face projecting bosses, nipples or Stringing guides t, of varying lengths and the Stringing itself.

of the racket where the channel for receiving the Stringing stripA is preferably deep, being short, while those at the throat end of the racket where the channel is shallow, being correspondingly longer, and the intermediate ones suitably graduated, and inL all cases being such that when thel strip is inserted in thechannel of the racket frame, the nipples project through corresponding holes 9 formed in the tubing for the Stringing and center properly therein. v The metal tube has these nipple holes 9 formed vin its opposing walls for the stringing and the nipples of lthe-string supporting strip extend through the apertures, preferably just beyond the cutting edges of the inner holes 9. 'I'he Stringing is woven through the Stringing vstrip and nipples and is thereby protected so that regardless of the angle at which it turns incoming out of the frame, it is secured from contact with the wearing edges of the metal.

As a result of my preferred method of fabricating a racket out of tubing and forming the Stringing holes by means of a punch press, as will bevlater described, the channel 4 has a flattened circular enlargement around each nipple hole formed by the punch die. The more elaborate form of Stringing strip Figure 7 is molded to conform to these circular enlargements l0 about the holes, thereby giving the Strip at the holes greater strength in all directions to resist the pressure of the awl, etc. instringing, while between these disc like portions l0, the band is narrowed to a minimum il to make possible the use of` a minimum amount of material with corresponding minimum weight, the saving of which is so important in the head of the racket. f In my simpler form of Stringing strip Figure "l, it is not necessary to have these extending disc portions and the band 5 can be run in a straight narrow strip the width of the imbedded fabric l and sufficiently wider than the Stringing hole as to prevent the strip breaking at the holes.

It will be understood that in Stringing a racket, each transverse String is pulled tight under great pressure and then held in place by forcing an awl l2 into the Stringing hole as in Figure l0, the awl then holding the string by wedging it against the walls of the Stringing Strip until the String is woven back into the next hole and then similarly held again on the other side of the frame by another awl. One of the main purposes of the fabric base of the Stringing strip is strip from breaking up from the great strain of further to reinforce the walls of the nipples or Stringing guides with the textile material, theA or wood and can be molded out of materials such Where it is also desired stili v as formed with a combination of phenol and` formaldehyde, or hard rubber (not vulcanized), or various lother suitable plastic compounds. Rawhide can also be formed for the purpose, but

from a manufacturing oreconomic standpoint, is not as desirable.

I t will be understood that the molds for these' formed strips are made in exact conformity with the racket frame. Each racket frame, as will be seen later, comes from a mold, which makes them all identical for'receiving the correspondingly molded Stringing strips. The opposite Sides of the racket frame are also molded to conform identically so that a standard Stringing strip will t correctly in either half of the racket head with proper conformity. The Stringing strip for the racket is so preferably made for half the length .of the racket from the point 5a to 5b, Figure 1 and Figure 3, so that two of the molded strips completely encircle the sides of the racket frame 'for the Stringing as indicated, -the ends meeting i at BPbetween the central longitudinal strings.

' nel 4 of the sharply curving racket frame.

Y Where idesired, however, the-strip can be .divided or cut into shorter lengths or asmany pieces as lwanted so as to include any desired number of nipple holes. Another feature of the particular thinness ofthe band 5 listo furthermore permit of suiiicient exibility in the bandto permit easy insertion of the nipples in the metal holes of the tube when the band is being' inserted inthe chan- The Stringing strip can be molded straight and flexed in placing, but is preferably molded to the exact curves of the racket-head as notedin Figure 3, but even so it must be exible for insertion of the nipples in the holes of the frame.

When the racket is ready to receive the stringing Strip within its channel, a thin coating of cementitious material 5d is placed either on the metal frame or on the contacting face of the i Stringing strip in the preferred .procedure and the Stringing strip forced firmly into this mastic bed and held securely so that it becomes rigidly and permanently xed, bearing solidly against 'the metal at all points. 'I'his is of particular importance so as to prevent the string Support giving after the racket is strung and so allowing the y the Stringing Strip can be strung and restrung. repeatedly, but when it is desired, after a number of stringings. to secure again the entire effect of a new racket in restringing the frame, the

1 old Stringing strips can be removed and new Stringing strips inserted in the racket frame, so

lengthened. y

Where it is unnecessary to have the Stringing strip 5 easily removable, the strip can have all or some of the extending nipples provided with grooved locks 8c, Figure 8, c ut or formed on opposite sides of or completelyencircling the nipv ples, directly under the inner face of the stringing strip, and in the preferred form. the nipple wall can be molded with an extending wedge shoulder 8dto .form these groovesv and .t0

strengthen the lock. The nipples in connection with these grooved locks are designed to be sprung into place in'pushing them into the holes 9 of the tube so that the walls of the nipples 8 are compressed and forced back until they spring f back and lock the metal wall Ih of the tube in `the grooves 8% securely anchoring the nipples smaller diameter inthe other nipples which have to accommodate but a single hole. This permits driving in the awl as inFigure 10 with greater ease and with less risk of cutting the strings, and also facilitates the Stringing work. The racket at the throat is left open between the Shanks as noted and is provided with the highly resilient spring and Stringing innovations introduced in my prior application #284,981 maturing into Patent #1,937,787, issued December 5, 1933. In this instance, I have, however, added a further .alternate development in my spring bridge by stamping the spring element Il, which automatically expands the throat, out of a fiat steel Spring and instead of passing the central longitudinal strings through this spring bridge to anchor in the Shanks of the tubular frame, I have provided for their anchorage inthe spring bridge itself. lI he spring bridge element I4 expanding the open throat is provided witha exible string support 5'c of similar construction to 5, but conformed to the Vwidth of .thesteel spring band I4 and having shallow nipples 8* projecting through receiving holes in the spring band of sufficient length to protect the strings from the metal edges. p The body of the molded string support 5c, it will be noted, is thin and exible, so that when the spring bridge is. exed in Stringing and play, as will be described, it will likewise flex with the spring.`

It will be observed that the open throat and racket head in conjunction with the spring bridge is designed to be contractable, and with this idea in mind, the 'racket is inserted, preparatory to Stringing, in a special vice I5, Figure 9,

`the vice being designed to contract the throat and head of the racket at will.` This can best.

be done by tightening the frame at the throat 'ated independently by any Suitable clamping means as IIia and I'I, or both can be similarly y rclamped jointly by |59'. that the life of the racket can be'indenitely In the Figure `1, I have provided the spring bridge I4 with an upward arc. In suchcase, I

clamp inwardly the throat of the racket atI I6,-

vas indicated with the grips I5 of the clamp and Figure 9. With the' spring arch H so raised and the throat and head of the racket contracted by the lower lclamping I6, the longitudinal Stringing is then woven in and pulled up tight in accordance with 'customary Stringing tighten the clamp at I1, bringing the sides of the racket head inward and forcing the outer end of the racket head outward. This 'brings tudinal Stringing, far greater than can .be attained by the Stringer in pulling up by hand the longitudinal Strings in the regular way. With practice. At this point, vI thenv prefer to further the head and throat of the racket so ,contracted 75.

, 70 about a still greater tightening of the longiand the longitudinal stringing given this extra super-tightening, the transverse Stringing is then strung in, in accordance with the regular practice. The racket being thus completely strung, the clamp I5 is entirely released.

It will be seen that the highly tempered spring racketframe and throat immediately attempts to regain its normal position. The tempered steel alloy tubing forming the open throat and racket head sides attempts to ily back into its former place and the powerful tempered steel spring bridge works in conjunction with same and to the same purpose, trying to' regain its normal yflatter arch position, thereby pushing ont the sides of the racket and expanding the head. The stringing will now be not only abnormally tight, but abnormally tense and resilient on its spring anchorage at all sides, ready to receive and return the bail with much greater speed and resilience than otherwise, as the entire spring frame has been set to act jointly with the Stringing. At the same time, the softer string supporting strip d and 5 relieves\the strings from the powerful spring metal strains at points of greatest stress, which may develop, and from the shock of sudden impact by having the proper amount of give and resilience in its own4 body. The central longitudinal strings, which receive the greatest shock and strain in the racket, are relieved at the moment of ball impact on the Stringing, hy the'spring arch it contracting and momentarily "giving to the strings als the stress is increased, only to then'y bach in position, the Stringing thus working after the manner oi a bow string in archery, y'the strings being whipped" by the spring trame and bridge in addition to their own resiliency.

lt is essential in connection with this highly` developed spring action es set forth in my previous application #234,931 maturing into Patent #1,937,787, issued December 5, 1933, that the .shape of the rachet head be so formed that its sides cooperate to sustain these spring leverages without undue collapse at diiierent points of the head. It is also 'essential that similarly .the rachet head should not lengthen vunduly or permanently from the intense stresses ci the tight stringing or that in lengthening it should not how out to a point at the centering of its tip and the rachet head lose its proper shape. All of these faults of distortion occur in the common wooden erachtet, particularly in the standardized pointed oval head, while the curve of the wood at the l'throat or shoulders oi the racket head, necessitated by the limitations of the material, is so gradual as to maire with the sides of the frame a at arch, which would cause the sides of the racket head to collapse inwardly if any such ending throat action as above described were attempted.

It will be accordingly noted that the preferred form oi my racket has more abruptly curved haunches at the throat than is common in other rackets which pursue the limitations and conventions of flong standing wooden construction. My rachet head is preferably straighter across the top or outer end, with the sides tapering in toward the outer flattened end, making the racket head preferably wider near lits throat end than at'the outer end and with strongly arched sides tending to more powerfully resist collapse when pushed outwardly by the steel spring bridge member I4. It will also be observed that the face or width of the tubular 'frame at the outer end of the racket at 5a or 5-5 as per sectional Figure 5, is preferably made substantially wider than the faces at the lower portions as for example 4 4, Figure 4. This, it will be observed, adds great strength to the arched end of the racket to resist the normal tendency of racket heads to bow outward and elongate pointedly. As a result, when the sides of the racket head are clamped inwardly and push the end of the racket head outwardly, the arched end of the racket tends to move outward as a Whole, instead of elongating into the pointed arch.

It will also be observed that -the Stringing of my racket head is not the customary rectangular crossing of the strings. On the contrary. while the cross Stringing is of the conventional parallel type, the main or longitudinal Stringing is made converging. By converging the longitudinal strings into the outer end oi the racket, a greater resisting force is concentrated to hold the already attened and strengthened end section so that it goes out as a unit without ,pointing or/undesirable distortion. This also tends, it will be noted, to divide the string stress among all the logitudinal strings, whereas in the other cases, the strain is generally upon a few of the central strings of the racket, which normally bear the brunt of the Stringing and stroking strain and are generally the rst tov break.

It will be found in connection with my rachet, that when the sides of the racket head are contracted by the clamps il as already` described, the longitudinal strings of the side portions, approximately one third of the area, on either side of the racket, are the tlghtest, whereas those lli of the central area, or about a third of the longitudinal strings, are noticeably somewhat less strained. It will also be realized, in connection with the design of the racketin Figure l where the spring bridge l@ arches upward, that the central longitudinal strings bearing' the brunt of the string Wear are particularly relieved. They are anchored in the spring arch ifi. This automatically springs upward on ball contact giving these strings momentary yslaclr at the moment of greatest stress whereby the abrupt shock of ball impact is relieved. IThe strings are then whipped tight by the recoiling spring, shooting the ball.

In connection with the sharply turned in framing at the throat ci' the rachet to form strong arches which will move outwardly :withoutl collapse on pressure from the spring member it, it will be understood thatthe anchorage ends of the bridge spring it, i. e. de, conform to and preferably extend along the inner sides of these arches to form strong reinforcements which are metaliically united, preferably by hrazingto the inner faces of the tubular frame. These end members t@ are formed in the stping of the strip spring steel of any length desired, diierent models being iinished with dierent lengths of reinforcing in conformity with their intended strength, weight, price, etc.

The shankl portions it of the frame preferably converge in the mi of the open throat so as to meet in contact at or before entering the metal ferrule 2, which houses and holds them in conjunction with the wooden handle 3. The

ferrule 2 is formed preferably from light sheety ing points I9. These points which are metal lically united, preferably by brazing, to the tubular frame Shanks are pointed to distribute the lzo stroking shocks coming down the racket head to avoid too abrupt a change in the strength with the corresponding risk oflsnapping the tubing. It will be noted that the upperportion t9 of the ferrule is straight so as to closely coorm to the tubing and hold same firmly within it for a denite distance. One of the purposes of this is to center and hold the loose ferrule on the tube shanks prior to brazing and heat treating so that the ferrule maintains itself in' correct position for brazing and does not have to be otherwise held in position. This brazing is located between the tubing walls and the'sides of the ferrule at i9 to it". When desired to further facilitate this holding of the ierrule in position,

the central portion of the ferrule it is indented inwardly to conform to the sides of the tubular shanks as indicated in Figure 1l and bridge the hollow formed. The ferrule can be located at any desired distance from the head of the racket, preferably far enough down to give a desirable length to the open throat for clamping and to produce the proper whip in the shanks in hitting the ball and to give a light head to the balance of the racket, as desired. Where a stiier action in the Shanks of the racket is desired, the errule may be raised to points closer` to the head. The head and the shaping of the shanks and the curve of the throat can be correspondingly modified to similarly conform to the higher point of location of the' ferrule. When the ierrule is set at the desired point, the racket can then be inserted in a punch press which stamps in the indentation at i9, tightly jacketing the tubing in the ferrule end and leaving it ready for the brazing at the sides, the brazing materiall being inserted and l extending down between the tube walls and the -1 ferrule sides at i9 to it asA faras desired for proper strength. If desired, the ferrule'and tube shanks can also be centrally brazed at lfvvithin` the ferrule by inserting brazing material there also.

In Figure 1, the handle 3 of the racket is in laminated strips a, 2th, 20, etc., of alternating layers of lbre and wood or two differentwoods, or other non-metallic materials glued together and rigidly held from subsequent separation by Y being driven into a housing formed by the ta. pered ferrule 2, the end of the handle and the grooves for the tubular shanks being rst coated with glue or other cementitious material, and the handle driven up tightly intotheferrule. The handle is then firmly pinned in'this position by pins 2|. These are preferably made non-metallic, using hard fibre, which requires no concealing plugs at thevends, as is the case with metal pins hitherto in use, and which do not tend to transmit vibration in the handle, the same as metal pins. By-pinning vthese through the front of the handle as indicated in Figure 1, each pin holding a tube separately, a very secure deep anchorage is secured not found in other steel rackets on the market, which are only pinned from the shallow wood sides. This extra security is the result of pinning each tube from the handie face separately through the thick part of the racket handle, pinning on the side of the handle not offering this thick anchorage.

The tubular frame ShanksV it extend partly down inside the handle in tightly fitting holes formed to receive them and continue beyond the point of the pins 2i any desired length. Where still further security is desired, a .further cross pin 22 can then be inserted in the opposite plane at right angles to that of pins 2l, this pin .also

being of fibre or non-metallic material, and

slightly below this point the tubing can then be terminated. The handle below the tubing termination is thensolid for at least part of the way as at @-6. The outer end can be hollowed out v y `handles toy split.` Where desired, I make the `sides of. my handles concave with rounded corners between as noted at 20e and 213i, as indicated in Figure 6, this feature giving a gripping point for the thumb and the hand bearings so that the racket does not slip and turn in stroking. The laminated material in the handle is preferably of alternatingly light and dark colored woods so as to produce a stripedv and handsome effect when flnished,and the number of laminations can be varied to suit the taste. The laminated construction gives both beauty and strength to the handle and the pins 2l 'can also .be located so as to be practically concealed by the stripes of the lamination. The laminated handle can be made in a` solid assembled section in' which the shank holes arebored from `the end and the handle slipped into the frame shanks as a unit, or they may be halved and jointedat the. sides or on the face. One of the features of my built uplaminated handle as shown, is that the racket can be jointed on the face at 20d, instead of at the side, in which case the joint is concealed by the laminated formation when" the two,portions of the handleare tightlyglued together about the shanks. The endI of the handle is finished with the customary leather butt ttt. Y p

In Figures 1,2, 15, and 21 are represented modied forms of the racket presenting certain specic advantages for particular cases. Where it is desired, Figure 12, the racket has the spring.

bridge it arched upward similar to Figure 1, but Where a different reaction is desired and a differ.-

4ent throat appearance, the spring |41 can in-- stead be arched to curve downward as in Figure 15. Where the vspring bridge s'o arches downward, the order ofthe stringingand clamping arrangement, asv previously described, ,is slightly modified. In this instance, the clamping and .I

contracting of the racket 4frame together at the the spring ,bridge Mb downward instead of upward as inrFig- ures 12, 9 and 1, and so tightening the group of central longitudinal strings anA chored in Mb. 'On this account,itis preferable in the racket of Figure l5 not to clamp the racket throat and sides together luntil the longitudinal strings of they racket are in place and pulled tight by hand. The racket is then clamped at it and l1, Figure 9, and the spring bridge Hb thereby pressed downward. It has already been pointed out how this clamping of the racket at il, Figure 9 tightens the groupof longitudinal strings on either side of the central area rather than the central group of strings, but in this in'- stance, it will be observed' that the forcing 'of the spring bridge Ilb downward also gives pronounced additional tightening to this main-group of central strings so that thertightening of practically all the longitudinal strings is thus securedr and approximately equalized. `After .the longiducing a super-tight racket in which tle various spring elementsand the spring 7trarne are .all set vtightly against thev Stringing,

`Where additional spring strength is desired bepreed spring bridges Mor i4", a recoil spring member can also be inserted in thethroatgof these rackets to increase the spring action. Figfspring element has a powerfully tempered steel' fnrevifss'hows in detail such a recoil spring, which 'can be used either with the convex spring bridge Figure l2, or the concave Figure' l5. The recoil alloy spring 23, which operates in a compression chamber formed by thetelescoping cylinders 2d and 25 which are preferably formed of aluminum, aluminum alloy, or other very light metal. These encasing members 24 and 25 'have projecting lugs 29 at their ends which'ginsert into corresponding holes found on'the inner sides of the Shanks of the racket throat.l Where the racket frame is of steel alloy heat treated to develop the .physical properties, high tensile strength, and vresistance to metal fatigue, .as in the preferred form of 4my frame, the recoil'V unit since it is of a llight metal of lower melting temperature than the heattreatingv requirements of the frame, is inserted after the fram is heat treated. 'This can be conveniently ldone spreading the throat of the racket andslippi g the' lugs or extending hooks 26 into the holes in 'the racket frame i. These inserted arms 2S; can then be bent back tightly in 'place by inserting a `.suitable tool at the open ends of the shank tubes, and the throat allowed to springv back in place,'contracting the recoil spring 23 into compression. When' the racket head is subsequently clamped, as already described, this recoil spring is' brought to its maximum compression and islthereafter working" against the string pull, to tighten :the strings by spreading the frame, and to. give on the ballimpact andinstantly recoil. This will greatly accelerate the resiliency of the racket onv the ball. In order to avoid all noise'in connection with the action of the recoil spring, the cylinder members 24 and 25 are preferablyprovided with a nonmetallic lining 27, which can be formed of nbre or hard rubber or other suitable material. These lie between the otherwise contacting metal members so that the noise and vibration yoi metal contacts is avoided. Where it is desired to use steel casings instead of duraluminum or -other light lower melting alloy, the recoil unit can be braced at its ends to the frame in addition to the anchorage into the frame of projecting members 26.

In my previous application #284,981, maturing into Patent #1,937,787, issued December 5, 1933, I have added great spring resiliency to the metal tubing of the frame, particularly at the throat in connection with the clamping, by brazing thin wire like members on the tubing walls of the frame, Where it is desired, these thin members may be stamped from steel alloy sheet and in connection with such procedure, I have provided, as in Figure 12, to form reinforcing members 28 on each of the two faces of the racket in one stamped piece with an enlarged end 29, which is formed into the shape of one-,half of a ferrule with interlocking edges which are clinched in conventional sheet metal interlock 30 on each side of the racket so that the pair so united form a.

yondfthat of the clamp-setfirame and the comferrule housing for thewooden handle. The face Y reinforcement of the frame tubing and the ferrule is thus formed out ot two pieces of stamped sheet 4metal placed on the opposite faces of the racket,

clinching the tubing tightly together at the point 29. The branching reinforcing members 28 unite in one piece below the throat and in forming the ferrule portion 29 are preferably stamped in raised relief for artistic edect, terminating in a point at the lower portion of what appears to be a separate ferrule 29, but which is the same sheetv of metal. 'Ihe extending reinforcing arms cf metal 28 running up the tubing are held in place by rings at points`3i and 32, which can be spaced apart at any given number of points, as desired. The rings may be either separately formed rings as 32 yslipped over the reinforcement 28, or they may be, and preferably are, formed integral with the` sheet 28 in the stamping. 'ilus is accom-l plished by stamping the metal at these anchorage ring points, as indicated in Figure 20, with ex-r tending arms 33 and td. The rings 3i are then 4their length. The entire reinforcement includthe rings are thus held nrmly in place for brazing and are brazed to the tubing in. this 'position along its length and around the top of the ferrule portion without the necessity oi any further anchorage. The points 2te are ground down to fade out at the end to relieve sudden strains. l I

In Figure l5, the ferrule 2 is of a type similar to that of Figure l, but also has a projecting prong itc formed on the opposite faces of the ferrule at the top, this' projecting point being bent inwardly so as to contact with the tubing and'cover the depression between the 'frame Shanks as they enter the ferrule. The tube Shanks are preferably in contact as they enter the ferrule.

Figures 16, i7, i8, and i9 show alternate forms for the spring bridge members it and ib, which can have extending ends to form spring reinforcements on the sides of the tubing as shown. These are preferably stamped from steel alloy strip and are, of course, drawn or tempered after ht treating to produce the proper spring action. In stamping them in a punch press from the steel strip, the holes db for receiving the nipples da of the Stringing strip 55C are punched out and beyond the termination of the arch, the central portion of the band is stamped out so as to leave only the outer edge members do,

which :form reinforcing arms which are bent to conform to the' sides of the frame to which they attach to form reinforcing springs on the sides oi' the tubing'. The reinforcements 36 preferably join together as noted at'their termination and form a hook 3l, which is located to anchor into the Stringing hole and is bent down and backward for that purpose. In this way, the spring bridge piece with its reinforcing extensions can be quickly assembled on the frame by `merely snapping the hooks 31 into the proper Stringing holes, the'stringing hole at such points Vbeing shapedE slightly larger on one side to receive the hook 31.

At the base of the spring bridge arch Il. a similar tongued hook 39 is formed in the punching, which similarly anchors into the Stringing hole at that point, the tongue having been previously bent back to hook inwardly. These four hooks 31 and 39 on the spring bridge are so spaced that they spring or snap `into place when the racket head and throat is very slightly contracted for that purpose. The racket frame released then expands against these hooks and holds the spring strip nrmly in place ready for brazing. The parts contacting along the tube frame as 36 and all other touching points4 are then brazed to the tube so as to thoroughly reinforce it and give the frame great strength at the lower portion of the head, where the strains are maximum and where the greatest strength is desired for hard hitting; and

where much torsion also has to be overcome.v

Where it is also desired to reinforce the sides of the tube framing below the bridge in the throat, as well as above it, I also stamp out the arms 39 from the metal stock between the members 36. These narrow reinforcements are then bent backward from the points 39a' and to the curve of the throat of the racket and in their stamping having preferably reinforcing connecting cross bridges at desired points as indicated at im. These reinforcements 39 can be of any desired length as determined by the length of the metal between 3b from which they are stamped and can extend as far down the sides of the tubing in the throat as desired, either part way or preferably to the meeting point of the tubes so that they contact with each other from the opposite sides of the'throat, and there press against each other so as to hold themselves firmly in place for brazing as shown in Figure 12.

Where the recoil cylinder Figure 13 is also used, the members 39 or if brazecl to the sides of the tubing walls form a further anchorage to which the ends of the cylinders 2li and 25 can be fitted by slotting so as to strengthen the recoil cylinder against lateral dislocation.

Where it is desired to reinforce the side of the tubing frame I above the point where the spring member M3 or Elib terminates in the joining of the reinforcing sides 3S in the point 3f shown in Figure 16 or 1'?, the strip steel can be stamped with an extending kmember Iii continuing on at 3l at both ends vas indicated in Figure 19. In

vsuch case, -the reinforcement becomes a single central reinforcement on the inside of the frame,

instead of the two parallel reinforcements 36.

The reinforcements I are stamped to extend around the nipple holes 9, which they are 4punched toA match so as to permit the nipples Y entire contacting length, the

t vto properly project just through them. This adds greater reinforcing at these weakest points.

It! is anchored with projecting tongues 3l similar to 3l' which are stamped and turned inwardly to hook into the nipple holes in the tube, and at the same time'form the hole in M for the nipples y 8 to project through. These anchorage hooks 3l can be placed as often as desired and intermediate stringing holes 9B perforated to conform to the corresponding holes `9, to which they t on the tubing. These extended reinforcing members 4I are brazed .to the tubing along their same as reinforcements 36.

In Figure 17, the construction of the spring bridge and reinforcement stamped from the fiat strip steel is generally similar to that of Figure 16. It is to be noted, however, that the reinforcing extensions 36, in this case, are of vary ing Width, the width at B adjacenty the Stringing holes on the tubing being wider than the intervening archesat 36h, so as to more nearlyequalarmere ize the strength of the reinforced tube by giving more reinforcement adjacent to the holes. To similarly still further equalize the strains in the racket head, the reinforcements 36 as they approach their outer ends. graduate to a narrower width so that as the strains on the racket head gradually increase on approaching `the throat, the width and corresponding strength of the reinforcement brazed to the tubing `gradually increases.

The spring bridge may be of a constant width throughout, or where desired, as indicated in Figure 17, reinforcing legs 42 may 'be formed in the stamping process by slitting the metal at this point and hinging the members so formed downward aty 52a to conform and braze to the inner faces of the tubing in the throat as noted in Figure 15. In this way the throat tubing can `be reinforced without applying separate spring members, which i's more troublesome. If it is desired to further stiften the fiexible bridge Ib at its center or weakest point, the projecting faces 39 formed by the stamping and bending away of the `reinforcing legs Q2, can be bentl downward as indicated along the dottedlines M, forming stiening side faces at the center of the bridge as indicated in Figure 22 between which and within which the Stringing strip 5c is snugly held.

In Figure 18, the terminating end of the spring kbridge and reinforcement Il or Mb is shown out of the hole, and so provides greater safeguard against snapping the tubing at such point.

In Figure 21, I show a racket of simplified throat construction. In this case, the spring bridge and metalreinforcement strips are omittedand the framingvl of the head formed with'the open throat, the shank portions I8 of the frame, meeting in contact and there brazed together at la substantial distance below the lowest Stringing holes and preferably at the point of entrance to the ferrule 2, althoughthey may meet in the brazed union at a point higher above the ferrule. .N

In making the racket, it should be understood the racket frame I is formed to the dotted lines I so that thehead of the Unstrung racket is wider across from side to side as indicated, while the throat forms an enlarged wide open V as indicated by the dotted lines, and not as shown `touch at the point 46 as shown Vin the strung racket, and the sides of the head above the throat are at the same time lcontracted inwardly by the clamping'll, Figure 9. The longi-` tudinal Stringing is this tightened as previously anziane to the dotted une with me Shanks spread rar apart in the extra wide open throat thus formed and then contracted so that the shanks come into contact at the point 46, ywhich is preferably close to the lowest stringing holes. is to give the frame head so -contracted an exceptionally strong spring action as the tempered shanks of the frame are exerting this outward pressure on the stringing. Furthermore, it has been demon-V strated by experience that in rackets of this Y kind, which are 'not reinforced with the bridge lils' spring spanning the open throat or at least by reinforcements on the tubing of the frame as 2B, Figure l2, that the repeated blows of the balls on the Stringing tend to permanently collapse the open throat and so loosen the stringing, particularly in the lower. portion of the racket head, if the'shanks are not in contact as described. This, however, is prevented when the shanks are clamped to a contact or very close to a contact at 46. because in that position the open throat is prevented from any further or any appreciable collapse after the racket is strung in such position, while at the same time the maximum expanding force'is exerted against the strings; lIn as much as the lowest holes for the Stringing guides of the central longitudinal strings further weaken the racket frame at a -ghly stressed point, I provide, when so desired, vbroad steel alloy encircling bands or rings il at that point. These encircle the tubing and are braced to the wall of the tubing, while they have holes for the Stringing nipples concentric wlth the holes in the frame tubing and are preferably ared or turned into these holes so as to leave ay cheered hole for the stringing guide or nipple.

Where it is desired to reproduce the eect of bam or stepped on partridge wood, the framing of the head, as it gradually increases in depth as it approaches the throat from the tip end of the racket head, may be stepped up at desired intervals instead of giving a gradual taper.

These steps are 'indicated at da, d, and Y, and

may completely encircle the tube or for advantages in manufacture, which will be subsequently described, appear only on the opposite faces or the front and back sides of the racket framing and fade out onto the sides oi the tubing. They may he spaced apart evenly, but preferably are gradually spaced closer as they approach the throat. Below the Stringing holes, the frame may, if desired, be stepped down again in thickness or complete diameter at a point as indicated f by dotted lines 43* giving a relieving glve" and whip to the The ferrule 2 in Figure 21 is stamped with pendant projecting members 49 on its opposite faces, which form an anchorage for a handle pin 2 i, which in this case is preferably a light metal such as duraluinin. It passes through the handle contacting walls of the two tube shanks I8 and rivets in the head of the pendant 48 on the opposite faces of the handle. At a point further down the wooden handle 3 is a pin preferably fibre or non-metallic 22B, which passes through.

the handle and the tubes from the side at a point above the termination of the tubing in the handle and with a driving nt. The tube shanks are thus This order may be reversed with the pendants 49 formed on the sides instead of the faces of the handle In the-case and 4then 2li is a transverse side metal pin 'and the pinning at 22n is secured by two nbre face 'because of the method of pinning at 2 le, to apply the handle and ferrule after the racket has been heat treated and without brazing. This permits of the finishing of the handle and ferrule and slipping it on after the racket frame is completed. In such case, the ferrule may be made of duralumin or other light low fusing metal or material, asl it is not exposed to the otherwise destructive heat treating temperatures necessary if steel alloy tubing is used in the frame. It is understood that'the handle is glued in its housing 2 and that the Shanks i8. are coated with glue in slipping the handle over them so that when the pins 2ll and 22 are in place, the racket handle is firmly secured-with anchorage pins in opposite planes.

In Figure 24 is shown a detail of a string guide or nipple for separate or single holes. In this case, the nipple is provided with a beveled or screw head 5I, which ts within a countersinking 52 of the metal holes 8. The stem 8 of the nipple can be provided with projecting shoulder loclnsv 04 similar to those of Figure 8, or as here shown, the projections may be formed merely by extending lugs on two opposite sides of the nipple, which insert through slots t in the tube and are then secured by rotating the nipple a quarter turn. For the latter purpose, the slot 52e for a screw driver is preferably formed in the screw head at right angle to the plane oi the lugs, so that when locked, the slot lies in the path of the Stringing, extending from hole to hole onthe outside of the racket frame, the stringing thus lying in the slot and preventing 'the nipple turning. Where it is preferred, the two opposite slots d in the chamfered metal hole may be omitted and the lockshoulder ed formed simply by a raised screw thread on the nipple stem at that point, so that the nipple can be screwed into place and thus locked securely, and yet easily removed for replacements or other purposes. It ls understood that the single string guides are also preferably cemented in place the same as the ing and protecting the strings and deadening the transmission of vibration to the metal. Raw'- hide or hard unvulcanized rubber can be used, or other non-spliting plasticly-formed material preferably having a textile element analogous to i3, Figure 8 incorporated therein. The single string guides are preferably inserted from the outer side of the frame, so as to be pulled inwardly against the head Eil by the Stringing, and the frame where such are used is correspondinglyformed and chamfered on the outer face.

of the two central strings, however, in Figure`21, rthe two last holes in the throat of the racket have the holes chamfered and the head 5l on the inside sides of the frame instead of the outside, as these strings in being pulled tight in the customary manner of Stringing, pull.

t the nipples If it is desired to omit the groove I from the outside of the frame except in the upper and end portion of the racket head where the strings must lie in a groove for protection, all the holes in the frame other than this upper grooved part may be countersunk or chamfered with separate string guides after the manner' of Figure 24. Where stepped enlargements of the frame are desired after the manner of Figure 2l and completely encircling the tube, a pleasing eiect may be ob-` tained in using such single hole stringprotection. the countersunk string guide heads 5l beingfiush with the face of the tube and carrying out the smooth lines. In doing this, a very handsome effect may be obtained by then encasing the tubing with a thin sheathing. In Figures 23 and 24, the sheathing 53 may be a wrapping or casing of thin wood veneer, Celluloid or Pyralin composition, or any other suitable material, and may encase both the tubing and the string protecting strip 5 or countersunk heads 5i of the single string guides, and be either in the form of a 'lointe'd` wrapping or a tubular sleeve drawn onto vthe frame. At the other endiof the'nipple, the sheathing preferably extends into the hole depression so that the edges of the casing material are covered and protected bythe slightly projecting nipple 8, as indicated in Figure 24. If,

it is desired, however, to cover the nipple entirely, thecasing may be extended over the end of the nipple as indicated in Figure 23, but this is less desirable in the matter of wear on the sheathing. However, if a process for Pyralin or other sheathing is employed where the sheathing coat is formed directly on the frame in a liquid or plastic condition, instead of being applied in 'tubular or sheet formation, thebcoveringl ofthe metal and cushioning elements is preferably continued into or within the holes for the Stringing,

leaving no exposed edges for wear orv chipping. The sheathing may be utilized to form a wood or bamboo effect and at the same time hldethe' na ture of the frames construction in relation tothe string supporting and protectingjelements. v

In Figure 23 is shown a modiiled arrangement whereby the sheathing can also, `if'desired, be

utilized and designed to form both the ornamental` iinish and the protecting string support, oi the. frame in Whole or part.

'Io successfully conform to channel d, a double thickness,` or with folded ends, additional thicknesses, for the string pro-- tective support may' be supplied in`lieu of the. special Stringing strip l5. This permits of the sheathing 53 in the casev o f Pyralin being formedfrom a at sheet instead of a tubular sleeve, z simplifying itsforming and application. To avoid chipping and tearing, it is preferred in the case of Pyralin and such material, to avoid exposed edges, for which reason a tubular sleeve would ordinarily be preferred. In this case, however,`

by butting the nat-strip edges againstvthe wall o f the sunken channel d, or under-folding them withy in the sunken channel, it will be seenthat this diculty of exposed edges is obviated. Thestringing holes may be punched in the Pyralin material 53 before placing it on the racket frame, a proA cedure which is also simplified by using the-nat sheets, and after it is properly pressed in place ony aivnaas weight limitations of a light racket head-the sheathing must be ex tremely thin and light, buttby lapping it in the guide then pressed and ared into position, as shown. This protects the edges of the sheathing at both ends of the Stringing holes and provides is thus provided. The string guide 8 as shownl may be of the same material as the sheathing or iif desired., because vof its edges being exposed orA because of its receiving more severe wear and usage, it can be made out of rawhide or molded vmaterial with or without'textile reinforcing material i3 asindicated, and instead of being iiared .at the outer end, ity may have a screw head similar to 5l, in whichcase a single layer of the7 sheathing can be used on the tube where jointless sheathing is used or where the ends are not lapped in the tube channel d. In place of lapping the Pyralin or other sheathing in the channel of the tube, the edges may be butt jointed in the channel and a narrow strip formed to the width and shape of the channel cemented over the joint. Where the sheathing material is used'for 8 and thematerial will permit, the edges of the flared ends may be folded` under 88 to strengthen and protectagainst tearing. The choice of these arrangements and the thickness of the materials 'can be determined by the specific needs in varied models and different weight considerations. The cementitious coat 5d throughout can be of an elastic material designed to retain its resilience and so addresilience to the string supports and thereby the strings.

Figures 25 and 26 show a modied form of frame and throat construction.. In this instance, the frame, as indicated, instead of having its changing thickness stepped oil' at right angles to the axis of the tube, is offset in a pointed or arrow head effect 54, not only for ornamental consideration, but to absorbv the stresses, gradually,

in changing thethickness of the tubing ratherv than' more abruptly as in the case of Figure 21.

This provides additional safeguard against the possible crystalli'zing or snapping of the thin tube walls. The arrow may point either upward orl than making it a more abrupt step approximately in one plane at right angles to the axis of the tube.

The throat expanding element shown in these `figures isy formed vof a flat steel spring band,

which is punched and shaped to form the uppery L' bridge member M and the lower Opposite curved bridge member l4 and the sides ld. The sides are preferably provided with stamped bent out prongs 55, which insert into corresponding holes in the tubular racket frame i. The sides Md 'in vvaddition are preferably also brazed to the walls -of 4the tube along the contacting surfaces or edges;4 'The doublespring bridge formed by I4 and Mc can be operatedras described already ydownward of theracket head and any other dej sign may be used which distributes the change: .vinvthickness of the frame over an area, rather for the previous bridge i4; or'can be provided A with avrecoil springjelement shown in this detail, which consists of a small rod 56 threaded at its.- lower portion on rwhich is screwed the r head of a .recoil cylinder 51, which tightens the tempered steel recoil spring 58 with turning holes t'x".` The other half of the recoil cylinder 59 ishriveted onto the spring IM. The metal bear- `ing surfaces within the* cylinders are lined with rubber or iibre or other non-metallic members B0, the same as 21, Figure 13. The parts of the recoil equipment are made of light metal, preferably duralumin, which is riveted on to the steel springs i4 and i4 after the racket'and the spring bridges have been heat treated, and is so replaceable.

Figures 27, 28, 29, 30, 31 and 32 show an original method I have invented for making tubu.`

lar metalracket frames. While these frames, already described, may be made with metal tubing in other conventional ways', the purpose 0i' my invention is to reduce the operation almost jentirely to punch press worlL--scnmeizhingr which has not hitherto been possible in the making of metal racket frames,-and so avoid the expensive processes now in vogue-as already set forth. 1

Figure 27 shows a piece of round frame tubing l which is the preferred formthough other shapes such as oval, rectangular, etc. can be used. The tubing is preferably of special steel alloy. The tubing is punched for the string guide holes as shown in Figure 28. It 'desired all the required holes 9 can be formed with one stroke of the punch press, where a punch and die seat is provided for each hole, or it may b e found desirable to punch one-half of the length ofthe racket head tubing at a time, making two operations on theone multiple punch die. The punchv Si preferably has a small pilot leadl E2 on it. The purpose oi.' the pilot lead is to bear on a small area of the metal'tubing in advance so as to facilitate the formation or the dimples S3 on the punch side or the tube, which becomes the inner face of the .racket frame. After t2 has vdimpled the metal, the cutting head ofthe punch tl makes the hole in combination with the die 64. The die forms a, round dat ring 55 around each, hole on what becomes the outside face of the racket frame, as already shown in Figure 7. It is to be understood that as the punch Si and 62 descends into the tube i, the-'whole tubing being unconned at the sides, tends to spread and ilatten out sideways. It is desirable so far as possible te raise and maintain. the mounds or knobs 63 between holes, which is formed by the dimpling 63, as these raised mounds strengthen the frame againsttortion, and it is understood that the frame in Figures 25 and 21 are preferably so provided, the same as indicated in Figures 1, 12, and 15.

Figure 29 shows an alternate procedure, which precedes the punching shown in Figure 28, if used. In this step, the tube l is nrst placed in a confining die in the form oi' a channel Si. A grooving die-61 operated by a punch press then forms a channel on one side oi' the tube B8 of desired depth. It also can be variable in depth at different points oi' the racket to suit conditions..if so wanted. Where the tube is so channeled before punching, the punching is then done as shown in Figure 30 similar to the operation described in connection with Figure 28, and its position on the die with the channel downward preparatory to punching, is shown. After the tube 4has been punched and the two opposite wa1ls brought towards each other by the punching, the tube is ready for bending. These opposite walls may touch adjacent the holes or may be held partly apart 'from each other, but in any event their Position is suiiiciently close to each other that the tube' can be bent without seriously dislocating the holes or causing buckling and stretching at the weak points o! the tube about the holes, as would be the cose if an attempt were made to bend a round tube or one in which the walls at the holes had not been substantially collapsed towards each other. The bending, in other words, is made'to more nearly approach that of a ribbon or a fiat bar contrasted with a round tube. The tube is then accordingly readily bent around a. form to the desired shape of the racket frame of the head and throat, without the customary and expensive methods involved' in tube bending. It is then ready for the'next .Operation shown in Figure, 31. l

'Ihis is performed with a ilattening. or molding die, the central portion of which is formed by the plate 69 formed to the exact shape of the interior area .of the racket thead. Around this form the punched, attened, and bent frame I is placed in position on edge as shown in section. On the outer side oi' the forming die is an adjustable form composed of movable plates indicated in cross section by 10. Plates 'I0 slide inwardly to correct positions contacting end to end' around and spaced away -from the central Y iorm 69. The several pieces of Il thus slide iny on theV supporting plate 1| to form the continuous form around and properly spaced away from 1 *the tube I already placed in position, as noted,

' around the center form 68.` The die l2, operated by a punch press, is then brought down upon the upward extending face of the tube i and the tube pressed downward so as to assume the final position and its finished form, shown in Figure 32, shaping itself against the dies es and is.

The inside and outside fong mers t@v and te, it 4will be observed rest on spr supports is and ld so that as the upper `fornrning member 'l2 presses down on the tum, the bottom supporting plate 'id exerts lar pressure on the opposite or under face oi the tube and the sprl` T13 and i@ permit the forms to carry downward with .the tube, shaping both the top and bottom tube faces simultaneously, giving the tubular frame its dna] shaping in the open channel between the forms 59 and 1li. Thus when the forms come to i'inairest on the bed plate 15, the racket tube is expanded sideways to the desired cross sections and the sides previously pressed inward in punching for bending are again pressed outward and the frame completely formed. Eachracket head so pressed'is identical with every other one, all coming through the same molding die in this nlshing process.v

' plates 69 and 'I0 are provided with projecting pins or teeth IG and 11, and as the tube is compressed downward by the press plate 12 so as to lill the form, the teeth 1I and 'I1 maintain the holes in a correct position and size so that they.

are all maintained oi' a correct diameter and in correct position. These pins may be shaped to' give any desired form or size of hole and can be varied at will i'or any position in the racket for special holes for special conditions, as for example the holes in the' inner face of the frame where the stamped hooks I1 are secured, can be slightly enlarged on the hook side by the pins 'It for those holes being so shaped. Similarly when the lock lugs 8d of the string guide shown in Figure 24 are used, the pins 'I1 have shoulders to form these receiving slots t in the tube wall, and are also shaped to form the chamfer b2 for the screw head If the channel t is omitted in any part oi the frame, the forming shoulders of 'it are correspondingly modified.

After the frame is so formed, the plates forming the outer form it are slipped backwards relieving the tube frame i, and the frame is sprung oi the tooth It and removed from the die.

As already described, the racket frame as in Figure l is of deeper thickness at the throat than at Vthe outer head, To accomplish this, it is understood that the die plates I2, t9 and It, and the bed plate 'i5 are formed for this convergence or other variations so that whenthey come to rest in the final position under the punch press, the graduating or changing thicknesses of the racket frame are produced. Similarly the distance apart of the opposing faces of the form @Si and Iii varies as desired to suit the changing width of the tubular frame. Any desired shapes canobviously be obtained in the forming in these molding dies andthe tubing made to form itself under the press pressure to the prescribed and varied form at all points throughout the racket head as predetermined. It will be observed that inthe typical form which also oers simplicity in die making, the surface of i2 and the corre spending bearing bed I5 are fiat producing a correspondingly fiat surface on `the two faces of the frame. Where it is desired. however, to have the two faces of the frame convex rather than fiat, the dies are correspondingly concaved toY the desired shape as indicated by the dotted lines 'iii and It. Similarly in the case ci the stepped oi racket frames similarto Figures 21 and 25, the stepping in any desired form is properly recessed in molding the surfaces of the bearing plates 'i2 and It', and also 69 and I@ where necessary, and the flattening and molding operation of the racket simultaneously produces the stepping 0E Y on the opposite faces of the frame, or maintains encircling steppings if same has already been formed in the tubing.v

In Figures 33 and 3d are shown two separate methods of forming the string guide holes. In 33, the section shows the typical form that the holes receive from the punch press in Figure 28. In this instance, the punch 6i punches the holes Q to the finished size for receiving the nipples of the Stringing strip. This takes a larger hole in the tubing than would be the case if it were not necessary to insert these protecting string guides, and'on that account, I use steely tubing of larger diameter than that employed in the other steel rackets on the market where the Stringing is not protected and which accordingly are forced to use objectionable wire Stringing. Where it may be desired, however, to employ a smaller tubing, as for example in the case of vsmall light racket heads for squash, badminton,

etc., I punch smaller holes in the tubing so as not to remove so much metal and to permit the use of tubing of smaller diameter. Then'. in the molding and ilattening process of Figure 3l, the

1pins 'it and 'il which are pointed or rounded to the full size of the larger finished holes capable of containing string guides, press back the edges 9b of the smaller punched holes as they are forced In this required size as shown in Figure 34 for the nipple inserts, and the metal of the holes being turned inwardly by the pins 'i6 and 'il as indi'- cated at l, and leaving more metal for strengthening purposes.

For the games of racquets, squash, squashY the racket head, I prov/ide a special Stringing l strip d@ corresponding to 5 shown in the previous gures, except that in this case, the strip is made sumciently thick and preferably projected and rabbetted at the sides so as to extend beyond the frame channel, as noted, cover the striking surfaces, and pad the contacting portions of the frame hitting the walls or oor surfaces, at the end and outer portions of the racket. In the lower portion of the racket head, which does not come in contact with the obstructions, the stringing strip is reduced to its thin form as indicated by the dotted line di, the stripbeing thus graduated from the thin portion into the thick portion approaching the end of the racket head. The Stringing also, as noted, is protected in sinkageein a groove di formed in the Stringing strip. Where it is desired to have the Stringing strip 80 rigidly or permanently anchored within the vtube after the manner of 8, -Figure 8, I provide on the walls of the nipple, the side groove locking ridges similar to those described for Figure 8 or 24, or as shown in Figure 34. lugs 82 which are sprung into place as the nipples of the Stringing strip are forced into the frame holes so as to lock on the first 9b edge or between the inner and the v cuter 9b edges.

` forms of tubes for my racket frames, wherel varying proportions of depth and breadth of the tubular frame is given the nished racket head for withstanding the varying stresses at difierent parts of the racket or for producing different aesthetic effects in the iinished rackets.

In Figures 35 and 36 a piece of preferably circular tubing i of constant diameter is used to form the racket frame for thev racket Figure 1, the dotted lines ic indicatingits original straight form before the changing of its depth and breadth at various points in the racket frame in the ilnal molding process already described per Figures 3l and 32. After the frame has been molded, it will be observed, as disclosed by the exaggerated diagrams, that the face of the frame is wide along the central portion of the racket head A (Figure 35) and then narrows in width as it approaches the throat or bridge point of the head B, the width. then increases back to the normal size of the tube in the Shanks at C and then enters the handle at D in its original roundstraight form. At the same time, the depth ofthe sides of the frame, as roughly indicated in '36, changes graduating from its minimum depth, which extends along the central portion A of the outer end, and then increases up to the maximum Buat the shoulder of the racket head (see Figure 2) and reduces to the normal diameter or depth in the shank C, which is maintained in the racket handle at D.A

In the case of the racket in Figure 2l where the stepped oil depths are obtained While using a tube of constant diameter, the' depth of the tubing, after the mannerof Figures 36 and 37, is

minimum along the ,end area at A and then tapers to a step at 48f, and then runs along straight or slightly tapered to the step-up at 48 and similarly to 48d, etc., the stepping to be repeated according to the number oi' steps desired, as for example 48 and b shown in Figure 2l, but omitted for the sake of brevity from the typical diagram The metal for these stepped enlargements is obtained, ,in this pase, by the corresponding narrowing of the race as noted in Figure 35, and by the change in depth of the channel 4, the channel being deepest at the end portions A and graduating shallower to B as the tube depth is increased. After the point of the string holes 8, which weaken the tubing, are past, the depth of the tubing again decreases at 48", the stepping descending and the tube shank again normal at the tln'oat and entering the racket D in its regular form. It will be observed that the shoulders of the racket adjacent the throat and bridge area which meet the greatest stro stresses are those given a'maximum depth for resistance over the area 4B to B of ldiagram S7, or correspondingly in Figure 21 the area 68 to 48".

In the plan of racket Figure 2l, it will be understood that the face of the frame can be tapered from a larger width at luf to e. smaller at A.

instead oi widening to the area A of Figure 35 as does the racket of Figure l.. 'This is optional and in the case of Figure 21 carries out the' tapering or stepped eiiect of the rest oi' the racket head where that eect is wanted. 'Ihis tapering in this end area idf to A is secured by increased deepening of the channel d as it approaches the end of the racket taking up the excess metal secured by tapering the face. Similarly the channel gradually shallowing as it approaches the points B and C gives moremetal for extending the depth of the frame at the lower joints and the step-up of the faces as air stated.

Where it is desired that this stepping should not be conned to the two feces oi the racket frame, but should completely encircle the tube., straight tubing of constant diameter cannot very well be used, and a more ex w .1. sive fre results. Where the extra cost is not e. consideration, however, the tubing is stepped by either expanding or swagging or progressively stepped drawing so that the results of diagram Figure 38 are obtained. The framein this case can have the channel i extending the full length of the stringing holes, the same as in Figures 36 and 3'?, or very attractive resultscan be obtained by using the chel for the upper lend of the rachet A-A and using holes 9 with chamiers b2 without a channel in the remaining side portions of the racket head. In this case, the standard Stringing strip with extending nipples is used in the channel 4 while in the chamfered holes, the string guide t of the type shown in Figure 24 with vor without lugs or screw locks id can be used. By

applying the sheathing 53 with a bamboo or wood iinish over the tubing and the countersunk guide heads or not, at will, as described for Figures 23, 23 and 24, a very beautiful eiect can be obtained concealing the construction ofthe racket and giving the appearance o'a light wood or bamboo frame of reduced dimensions impossible to obtain in a Wooden racket of requiredstrength.

In Figure 38, it is not necessary tochange the original diameter of the tubing in order to obtain the final step oil from A'-A for the -upper por-4 tion of the racket head. 'I'he reduced diameter at this point to give the step down at 83 can be secured by utilizing the metal to form the deep channel 4 over this length o! the tube ne for the Stringing strip l and the sinkage of the strings. This saves additionalg, drawing, or expanding and is taken careoi in the molding process.

In Figure 38, where it is desired to provide further protection against crystalizing or possible ultimate snapping of the frame at the steps 8S, which are at right angles to the longitudinal axis of the tubing, I provide instead a diagonal steps ping those at one end ot the tube pointing oppositely to those at the other end of the tube. so that when the straight tube is bent into the form oi' the racket head, the two sides of the head are '.wtricaL These diagonal steps tend to bute the shock to better advantage than the right le step up.

Where a still better distribution o1' the shock is desired, even if at more expense. and where a further variety of .i tic edect is sought, the

' stepping of the tube is done with irregular lines encompassing the tubing at each step. These can be oi a variety oi forms, but preferably are oi a chevron form with corresponding vs on opposite sides meeting to encircle the tube. The stepping of thisl ro gives an ideal distribution oi" shock and vibration resistance in the trame. Such an arrangement is shown in Figures 25 and 39 and the Vs in the graduated tube form a step-up completely encircling the tube. In the use of straight tubing after the manner of Figure 37, the V's can also be formed showingproniinently on the upper and lower .faces of the frame and ing out on the sides after the manner of the straight steps shown in Figure 37.

ere the step edects are not required, but the increasing streh of the tapered tube to further stiien lower portions .of the racket head is desired, tapered tubes oi the type of Figures 40 and ti can be employ and can be formed from strip sheet metal cut to proper patterns folded and I united with a central brazed or welded seam 35,

which produce the tapered i'ormation wanted and. nu'. of the tube being in a single piece for its entire length, the seam, being arranged to. come' in the channel or channel sides of the rachet frame. Where a seamless tube is used, if

drawn the tube can be de in two pieces with a brazed butt joint @t backed with a concealed interior braaed nipple til'. If, however, the tapers oi the tube are done by expanding the enlarged parts or of swagging the decreasing parta-the tubes can be made of a single piece without the joint dit. It will be understood that the centrally jointed, two piece tube construction can,

ii' desired, be likewise used for rackets such as those in Figures 38 and 39, etc. l.

lIn Figure i0, the tube'oi changing or tapered diameter maintains a straight section at the end for entrance D to the handle 8, which facilitetes the boring of the handle for tting the tube Shanks. Similarly the central portion A-A' is maintained in straight or untapered diameter for the outer grooyed end of the racket. The tube may be groved for any desired length, and preierably after the manner of the racket shown in Figure l., otherwise after the manner of Figure 38.

In Figure 41, the tapered tube, for simplicity sake, is tapered throughout from the end to the center ,where the tapering reverses. In this case, the handle 3 has to be specially formed for the tapered shanks. This occasions extra expense, but offers advantage in the wedge formation of the tubing in the handle, which tends to give theV Y v @,l'l handle a stronger hold on the 'si n y: in addiformed on lines diagonally disposed to the axis tion to the regular pinning. The handle in such case must be of the split type of two pieces glued together on the shank rather than the straight bored singletype, which can be slipped on the straight Shanks in one piece, when so desired. This tube frame is, oi course, also grooved where desired and. preferably at the A'- section in any case.

Where the more elaborate forms of stepped and Y.

ornamental tubing already described are exn= ployed and the flattening and molding process, previously outlined, used, it will be understood that the molding forms l2, lil and bt, itl are shaped to conform to these final intended effects when the shaping of the tube is completed in Figure 32. Advantage can be taken of this in the prior swagging, expanding or drawing of the tube in its changing shapes, so that in these pre liminary processes the nal fo need only be roughly approximated or approached and the iinished lines and exact form then given in the molding step of Figures 3i and 32. l 5.11: be found particularly helpful in certain cases, making possible exact shapes, which might not otherwise be easily obtained in the aforesaid preliminary preparations of the tube.

As already out1ined,it is understood that the racket frame when e is' preferably special steel alloy tubing, although other metals or materials can be used. The steel alloy. which is highly desirable for strength, resistance of fatigue, and minimum size, iS heat treated after coming from the finishing form 3i?. After being heat treated and quenched, the frame is drawn at any desired temperature for the preferred stiffness or enibility of the frame. Where it is desired to relieve the strain on the lower portion of the head or the throat section of the frame where weakened by holes, I preferably give the Shanks of the .frame above D and below C,

, as indicated in the diagrammatic gures, a draw at a higher temperature than the rest of the frame, thereby giving a whip at the lowest point of the racket frame and a greater ductility which permits the frame to bend more at this point and relieve the points higher up weakened by holes for the Stringing guides and Stringing.

-In Figures 42 and 43 showing a complete racket, the tubing hasthe straight Shanks as described in connection with Figure l and the throat and head portions tapering to a changing diameter. The head portion is formed of tubes metallically united at A as heretofore de- 4liti scribed inl combination with the metal element 2li as set forth with Figure l2, completing the built up and strongly reinforced frame and at the same time forming integrally therewith the housing socket 29 for receiving and firmly hold' ing thehandle 3. The socket 29 is provided with the pendant members d@ extending substantially downward of the handle so that with a minimumof metal the pin anchorage 2de can pin the handle at a point of increased and substantial thickness greatly improving the strength of the union as compared with other methods and my described in connection with Figure 21.

The racket head is actuated in the expanding of the open and contractable throat by the Spring bridge It and the extending reinforcing members 36 and likewise the recoil cylinder 23, all as described in connection with FiguresiZ, 13 and 16.

In Figures 44 and 45, the tubing forming' the vframe is provided with a'changing diameter by means of stepping similar to Figure 21',`but here of the tubing as in 25, so as better to distribute the abrupt strains to which it is subjected in play and likewise toy present a pleasing appearance to the eye. The outer portion of the frame is provided with a groove 4 in which the cushion nipple strip rests keeping the Stringing free from abrasion along the outer portion of -the head where it 'often strikes the ground. LThis portion of the racket is similar to that described for Egures l, 2, 3, etc. In the remaining or stepped portion of the frame, the Stringing is secured and protected from the tubing by the insert nipples having the heads 5i lying flush in the formed recesses b2, all as described and shown in connection with Figure fd.

The open and contractable throat of the frame is expanded by the spring bridge member Mib as shown and described in vconnection with Figure 17.

The tubular frame and the handle of wood or other suitable non-metallic material are joined with the metal ferrule 2 as shown and described in connection with Figures l5 and 2l, etc.

While I have shown and described my invention in a preferred form, I am aware that various changes and modifications may be made therein without departing from the principles of the invention, the Scope of which may be determined by reference to the appended claims.

l claim as my invention: l

l. For use in a racket, a string guide of nonmetallic `material for insertion in the Stringing holes of the racket frame, formed with an eny larged head at one end, said head being seated in a chafmfered depression in a side of the frame so as to protect the guide head from abrasive injury, hold same more Securely in place, and permit the strings passing from one hole to another on the outside of the racket frame to lie in contact both with the surface of the frame and that of the guide head.

2. For use in a racket frame, a protecting string guide for insertion in the Stringing holes in the frame, said guide being removable at will and being held firmly in place in the Stringing hole by locking or engaging members formed on the guide.

3.1m a racket for hitting games, a metallic frame encased in a non-metallic sheathing, said sheathing extending'into recesses formed in thev racket frame adjacent the Stringing holes', and a non-metallic cushioning guide extending through Said Stringing holes and` over-lapping the edges of said sheathing.. 4. A racket frame having a flexible spring bridge spanning between the opposite sides of f by impact of theball upon the Stringing 'thereby increasing the resilient action of the Stringing.

7. The method of forming a racket frame made of tubing whereby the holes are rst formed while the tubing is. in its Straight or unbentvform, and the tubing partially attened, the tube being then bent tothe contour of the frame while in

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